Ballistic primer

ABSTRACT

A totally combustible primer unit having a completely enclosed and protected primer mix for consumable ammunition systems and which are safely adaptable to mass cartridge assembly or production techniques.

United States Patent [191 [111 Evans Apr. 30, 1974 BALLISTIC PRIMER 3,486,453 12/1969 Smallwood 102/865 [75] Inventor: Edgar L. Evans, Washington, Minn.

[73] Assignee: The United States of America as f' Exami'fer Ben-iamin Bol'chelt represented by the Secretary of the ASSZSHZHZ ExammerThomas H. Webb Army Washington, DC Attorney, Agent, or Firm-Edward J. Kelly; Herbert [22] Filed: Oct. 8, 1968 Berl [2]] Appl. No.: 765,841

57 ABSTRACT [52] US. Cl. 102/865, 102/45 1 [51] P Cl F42! 1/04 F42b 3/10 F42C 19/08 A totally combustible primer unit having a completely [58] Field of Search 102/865, 45, DIG. l enclosed and protected primer mix for consumable ammunition systems and which are safely adaptable to [56] References C'ted mass cartridge assembly or production techniques.

UNITED STATES PATENTS 3,320,887 5/1967 Quinlan et a]. 102/45 3 Claims, 5 Drawing Figures BALLISTIC PRIMER The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to ballistic primers and, more particularly to a combustible primer unit associated with consumable ammunition.

One of the objects of the invention is to provide a totally combustible primer unit that can be safely assembled in consumable ammunition.

Another object of the invention is to provide such a primer unit in which the primer mix is sealingly encapsulated with combustible material a portion of with being subject to penetration by a firing pin.

These and other objects, features and advantages will become more apparent from the following description and accompanying drawings in which:

FIG. 1 is an sectional view of a combustible primer unit embodying the principles of the invention.

FIGS. 2 and 3 are sectional views of the molded cup and cap members of the FIG. 1 unit.

FIG. 4 is a view similar to FIG. 2 with the primer pellet pressed into the cup member.

FIG. 5 is an sectional view of the FIG. 1 primer unit assembled into the base of a cylindrical caseless round of ammunition.

The encapsulated combustible primer unit, shown generally at (FIG. 1), basically includes a molded consumable cup member 11 (FIGS. 2, 4) constructed of a mixture of small grain propellant, preferably a tightly compacted flake and ball propellant structure or mixture, and an abundant amount of colloidian solvent binder, a percussion sensitive primer mix 12 (FIG. 4) pressed into the cup central recess 13, a molded consumable cap member 14 (FIG. 3) having an anvil surface 15 provided with an annular peripheral recess 16 so as to be matingly pressed into the cup recess over the primer pellet 12. An annular combustible adhesive seal element 17 is provided intermediate the mating surfaces of the cup peripheral flange portion 18 and the cap peripheral recess 16. Thus, the primer mix 12 is sealed or protected from the environment and from leakage and is centrally fixed in a configuration suitable for optimum penetration by a firing pin having a predetermined effective length.

The cup central recess 13 is defined by the peripheral ring portion 18 and a spanning continuous thin base or rearward surface portion 20 which is of a tightly bound structure that is extremely brittle upon drying, thus permitting optimum penetration and fragmentation by firing pin impact to provide ready fuel for propagation of the initial primer ignition. Preferably, the cup recess 13 is 0.030 in. deep and 0.250 in. in diameter for a given caliber round of consumable ammunition, and the peripheral recess 16 of the mating anvil or cap surface 15 is 0.015 in. deep to be suitably received in the cup recess upon inversion and assembly prior to use with a firing pin of given effective length.

The molded cap member 14 is constructed of a relatively coarser type of propellant, preferably extruded in tubular form, than that of the cup member. The amount of solvent binder contained in or near the cap anvil surface 15 preferably is less than that adjacent the tightly constructed base 21, such that the anvil portion is loosely bound and, upon impact of a firing pin penetrating the thin cup base 20 having a thickness of 0.015 to 0.025 inches, will assist in or intensify ignition of the primer mix 12. The cup base 20 is thin enough to allow penetration, yet sufficiently thick to afford maximum protection.

The combustible encapsulated primer unit may be separately shipped and subsequently assembled in the manufacturing and assembly process within a caseless round 22 (FIG. 5) of combustible ammunition whose rearward surface 23 has been centrally recessed as defined by the round internal annular surface 24 and the annular rearwardly facing internal seat 25 of a consumable support tube within the caseless round.

Various modifications, alterations or changes may be resorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A totally combustible primer unit for consumable ammunition systems, comprising a molded consumable cup member having one surface provided with a central recess defined by a thin base portion and an annular peripheral flange portion, said cup member being constructed of a mixture of flake and ball propellant with a solvent binder,

a percussion sensitive primer mix in said cup recess adjacent said thin base portion, molded consumable cap member having one surface provided with an annular peripheral recess, said one surface of said cap being seated within said cup recess and against said primer mix to serve as an anvil for a firing pin upon penetration of said thin base portion of said cup member, said cap member being constructed of a coarser propellant than said cup member, said one surface of said cap member containing less solvent binder than its base, and

an annular combustible adhesive seal element disposed intermediate mating surfaces of said cup peripheral flange portion and said cap peripheral recess,

so constructed and arranged that said unit may serve as an igniter sub-component for a consumable ammunition assembly.

2. A totally combustible primer unit for consumable ammunition systems, comprising a molded consumable cup member having one surface provided with a central recess defined by a thin base portion and an annular peripheral flange portion, said cup member being constructed of a mixture of small grain propellant and a solvent binder, percussion sensitive primer mix in said cup recess adjacent said thin base portion, molded consumable cap member having one surface provided with an annular peripheral recess, said one surface of said cap being seated within said cup recess and against said primer mix to serve as an anvil for a firing pin upon penetration of said thin base portion of said cup member, said one surface of said cap substantially filling said central recess of said cup, and an annular combustible adhesive seal element disposed intermediate mating surfaces of said cup peripheral flange portion and said cap peripheral recess,

so constructed and arranged that said unit may serve is constructed of a coarse propellant than said cup as an igniter sub-component for a consumable arnmember, and said one surface of said cap member conmunition assembly. tains less solvent binder than its base. 3. The structure of claim 2 in which said cap member 5 

1. A totally combustible primer unit for consumable ammunition systems, comprising a molded consumable cup member having one surface provided with a central recess defined by a thin base portion and an annular peripheral flange portion, said cup member being constructed of a mixture of flake and ball propellant with a solvent binder, a percussion sensitive primer mix in said cup recess adjacent said thin base portion, a molded consumable cap member having one surface provided with an annular peripheral recess, said one surface of said cap being seated within said cup recess and against said primer mix to serve as an anvil for a firing pin upon penetration of said thin base portion of said cup member, said cap member being constructed of a coarser propellant than said cup member, said one surface of said cap member containing less solvent binder than its base, and an annular combustible adhesive seal element disposed intermediate mating surfaces of said cup peripheral flange portion and said cap peripheral recess, so constructed and arranged that said unit may serve as an igniter sub-component for a consumable ammunition assembly.
 2. A totally combustible primer unit for consumable ammunition systems, comprising a molded consumable cup member having one surface provided with a central recess defined by a thin base portion and an annular peripheral flange portion, said cup member being constructed of a mixture of small grain propellant and a solvent binder, a percussion sensitive primer mix in said cup recess adjacent said thin base portion, a molded consumable cap member having one surface provided with an annular peripheral recess, said one surface of said cap being seated within said cup recess and against said primer mix to serve as an anvil for a firing pin upon penetration of said thin base portion of said cup member, said one surface of said cap substantially filling said central recess of said cup, and an annular combustible adhesive seal element disposed intermediate mating surfaces of said cup peripheral flange portion and said cap peripheral recess, so constructed and arranged that said unit may serve as an igniter sub-component for a consumable ammunition assembly.
 3. The structure of claim 2 in which said cap member is constructed of a coarser propellant than said cup member, and said one surface of said cap member contains less solvent binder than its base. 